MX2010013306A

MX2010013306A - Heat conduction composition.

Info

Publication number: MX2010013306A
Application number: MX2010013306A
Authority: MX
Inventors: Klaus Keite-Telgenbuescher; Anja Staiger; Florian Meyer
Original assignee: Tesa Se
Priority date: 2008-10-01
Filing date: 2009-09-23
Publication date: 2010-12-21
Also published as: KR101630732B1; KR20110065423A; JP2012504667A; EP2283069B1; DE102008049849A1; CN102159633A; US20110168376A1; ATE548415T1; CN102159633B; EP2283069A1; US8911642B2; WO2010037674A1

Abstract

A heat conduction composition is proposed, comprising at least one polymer and a heat-conducting auxiliary material that has an especially high heat conductivity and at the same time has a high mechanical strength. To this end, the heat-conducting auxiliary material comprises particles that in turn are made up of primary particles and that have a mass-specific surface area of 1.3 m2/g or less. Also described are a heat-conducting surface element manufactured from said heat conduction composition as well as application possibilities thereof.

Description

HEAT CONDUCTOR COMPOSITION Field of the Invention The invention relates to a conductive commutator comprising at least one thermally conductive poWder, and to the thermally conductive use for sheet-like production, thermally conductive also refers to a similar, thermally conductive element as such strongly conductive, and to the same use of heat inside electronic devices Background of the Invention In many areas of controlled heat technology it has a part to play. The totality of the problems found Examples of heat sources and electronic assemblies whose operation, and also heating elements of c, and also containers in which an exothermic ca is carried out.

Typical heat sinks are e ectors (such as, for example, chilled bodies, cooler / fan, chill or Peltier elements combinations) and also any which are heated (e.g., thawed frozen areas, such as tile channels ficies in the automation segment tria of aerospace travel).

A typical problem refers to the thermal deviation that is produced, based on the res- toration of the components in an electrical circuit.

This class is achieved by means of an inter-layer placed between the heat source and the dissipation and which improves the heat transfer between the heat sink and the heat sink, so that a particularly large thermal loss is diverted.

The intermediate layers used are thermally conductive generators, which are applied to the assembly and to the cooled thermally conductive element, are composed of materials of the fluid matrix, such as polymeric r of low molecular mass. For thermal increase, the processing aids are added in a sufficient amount to these matrix materials. The systems are usually highly deformable, for the surface of the heat source and the surface Drivers have emerged as something particularly advantageous. These systems generate mixtures of polymers with additives (known polymeric), which are adapted in terms of their thermal conductive polymer properties are typically provided in the fluid adhesive system or a resilient adhesive system. such polymer blends can particularly obtain insulation of the heat source and the heat sink, additionally for many applications in the electronic segments.

Adhesive fluid systems are already exemplary, in the form of liquid thermal adhesives or liquid pastes. The liquid adhesives that are initially applied to the subst If they are measured with sufficient accuracy, during the union of the heat source, they exhibit a behavior that can not be controlled by a sensor. As a result of this, the intimate layers do not have a homogeneous thickness and, in excess, may arise at the edges of the additional advantage is that the fraction of the adjacent conductors as a proportion of the thermally conductive do can be selected relatively. high, for sufficiently good thermal impact on intermediate layer, and this, in turn, reduces amp resistance of the liquid adhesive bond.

Adhesive systems sensitive to pressure, for example, in the form of labels p P O 942 059 Bl, and EP 0 942 060 Bl describes, pressure sensitive ingredients which are based on pressure-sensitive acrylic acid or methacrylic acid of this kind are their thermal stability particularly high during aging. For high bond strength (more particularly high shear strength), the pressure aids contain comonomers which are free acids, examples being acrylic methacrylic acid.

To produce a thermally mixed mixture of a polymer matrix system of these polymers the sensitive adhesive systems are combined (compounds) with the readily conductive, and then, where appropriate mix, which should usually be done as much as possible, to prevent the form in the final product, as might occur during evaporation of the solvent. Before this mixed in the dispersion, the polymer matrix is not dissolved in the medium of the dispersion, but instead is suspended.

For mixing in the molten material, the polymer matrix is softened by high temperatures, the mixing temperature is selected such that it is in the vicinity higher than, the softening temperature is less a part of the matrix system In such conditions, this part of the metal system has a significant viscosity as in the process. However, if a particularly high lead is to be obtained, in the case also of the adhesive adhesive systems, this is achieved by the selection of a day of the thermally conductive adjuvants of pressure-sensitive adhesive, and this, the reduction of the resistance of the internal joint union (cohesion) of the system ble to the pressure.

This reduction in the strength of the problematic joint, however, when the system ble to the pressure, as well as one that has thermal uctivity, will be electrically isolated if the adjuvants with a particularly good conduction comprising such metals, gold , aluminum or copper, for example, no pu ea of metallic materials.

The thermally conductive adjuvants used, include, in particular, or nio (Al203) and boron nitride (BN). This is particularly preferred considering its availability and taking into account the barter favorable costs and thermal conductivity that can be with the typical non-metallic adjuvants ta le, for example, use silicon dioxide or titanium (VI) (TiB2) , titanium silicon nitride (T1O2), magnesium oxide (MgO), ((II) (NiO), copper (II) oxide (CuO), and O (III) (Fe203). In addition, a large number of metallic diamonds are used as sub-rails for thermal conduction, the examples MgO), Zr02 (Y203), aluminum titanate (Al2Ti05), It is an object of the present invention, by making a thermally conductive composition a good thermal conduction and at the same time thoroughly thermal, and to eliminate these dests previously, offering more particularly good and durable thermal cto with the surface e of heat and / or a heat sink.

This object is surprisingly achieved thermally conductive location of the specific description type, in which the thermal adjuvant comprises particles which are primary compounds and which have a surface area based on the mass of 1.3 m2 / g or cularly for such physical particulate adjuvants. specific less than 1.3 m2 / g, which lead to conductivity or that a larger surface area due to a heat transition surface more leads to the assumption of an improved transition from the matrix polymer to the thermal adjuvant.

The experiments at this point, while involving a thermally conductive composition with very high energy, of this class, sufficiently high internal ion, only individual adjuvant molecules are usually accumulations of the individual particles and therefore have a superfluous surface. irregular that is not smooth. Only with one is a three-dimensional particle of this kind are these particles fixedly, in polymeric structural terms, so that the thermal composition Highly elevated, at elevated temperatures, s the viscosity of the polymeric matrix going, until ensuring a total stable cohesion.

Particularly high conductivities can be achieved for the thermal composition if the thermal adjuvant particles have a still lower specific surface area of no more than 1.0 m2 / g.

In an advantageous embodiment, the thermally conductive particles are initially boron nitride oxide alumina particles. As a result of the inert adjuvants, the thermally stable, highly chemically stable compositions are ob which, furthermore, are advantageous from the points of the economy as well as from the environment. or. In this way, it is possible to prevent the removal or gelation of the polymer components in the acrylic acid or methacrylic acid is within the composition thermally can still occur in the mixing apparatus, and sharp increase in viscosity. Where one day of the alpha-aluminum oxide is taken in which results also continue to have outstanding qualities. In contrast, pads based on acrylic methacrylic acid esters, it has been found that, if the gamma-aluminum or beta-aluminum oxide fractions are 5% by weight, gelation or crosslinking occurs as early as in the eduction of the adjuvant in the molten material, the resulting thermally conductive before thermally conductive as a thermally conductive proportion therefore low power, thus making possible highly thermally conductive thermally conductive It is particularly useful in this case if the only conductor is present in the conductive conductor in a fraction of at least 70% by volume, more particularly at least 50% by volume, based in each case on the thermally conductive adjuvant. in the commically conductive. In this way, total thermal conductivity is ensured fast heat transfer from the heat sink source. This can be attributed to a high thermal conductivity of the conductive components of this class, but by As a result of this design of the thermal adjuvant with the heat source and with the disi is in effect still further improved the particles, in the first place, are sufficient to conform exactly to the shape of the heat source and the Secondly, they are still sufficient to achieve a high total thermal conductivity for the internal cohesion of the conductive commutator.

In order to improve the possibilities of the thermally conductive composition particularly useful for the thermal composition which is designed as an adhesive as an adhesive selected from the pressure sensitive adhesives, the In this manner it is possible to adapt the thermally conductive properties to a similar one and within a wide range, speci? c, its cohesive and / or adhesive properties, as well as the ability for the pro-adapted ones by means of the use of suitable monomers. In addition, the polymers are advantageous in that they can be combined with a particular ease and then applied to the molten material, further simplifying easily the processing of these systems.

It may also be useful if the thermal composition further comprises an adjuvant added to a material for the change of phase. With material phase change materials it is possible iormente. With the help of this element, they are thermally conductive, an interlayer produced in a particularly simple manner of heat and a heat sink, the layer efficiently irrespective of the heat produced in the f and operates reliably in this case, the present invention pro s the use of the thermally inferior composition to produce a similar, essentially conductive element, whereby it is possible to produce an element similar to a thermal sheet that can be connected without problems to the heat sources and dissipates them r, where an adhesive bond establishes Finally, the use of the above thermal composition is proposed for the trans It is desirable that it comprises at least two components and that it has a thermal conductivity. The thermal efficiency of a substance is determined by the local heating of its clothing through the substance., and because of the capacity of the substance carrying the thermal energy by means of the coke, in the form of heat. The conductivity typically is determined as a constant of the temperature of the tooth, especially thermal activity or the coefficient of conduction (specific), which is assigned to the symbol? (lambda), L, K or? (kappa) and the unit W / (High thermal value is considered to be a thermal conductivity that the thermal conductivity of the mixtures These are particularly useful in the range of application time, so that none of the unproposed chemical properties are brought to any notable extent in the composition. Sin does not exclude the possibility, in a commutative conduct, of a long break to the composition as a result of the kind that occurs also with the known fluid heat systems. In addition to the thermally conductive condition of the invention, there will be a deliberate chemical change, such subsequent clogging which is carried out for refining after the thermally applied composition is applied to the surface of the heat sink source, or to a transition phase co of the thermally conductive composition its form These include not only low molecular weight and resins but also high molecular weight metals and examples of polymers including these based on natural polymers, synthetic rubbers and / or the polymers based on the acrylate rilates.

"Based on" or "based on" means in the meantime that the properties of the mixture are at least largely polymerized by the pro-mers of this polymer (known as the), although this, of course, does not exclude the these properties by means of the before or modifying additives, or of additives, in the composition. In particular, this is the fraction of the base polymer with a proportion The polymers comprising additions with acid groups are advantageous in particular.

Particularly suitable are the crilate polymers which can be obtained, for example, bristling with radicals and which are based in ally on at least one acrylic monomer from the CH2 = C (R1) (COOR2), wherein R1 is H or a selected radical. from the group of alkyl radicals of ituides or unsubstituted, branched or unbranched (advantageously the alkyl radicals of alkyl radicals of C to Ci4 or even the radicals to C9), but can also represent optionally Specific examples, without being desired by this description, are methyl rilate acrylate, ethyl acrylate, acrylate, iladamantilo In addition to at least one type of monomer, polymers can also include comonomers, which are polymerizable with at least one ion, such as functional vinyl compounds, maleic anhydride, styrene, co-eners, vinyl acetate, acrylamides, photo double bond anointing, and the like.

According to the invention, at least one as a matrix for the thermal adjuvant. An auxiliary (adjuvant, additive) is a principle that is to be any substance attached to the polymeric constituent (the polymeric polymer phase) of the composition thermally co exerts a deliberate influence on the functionality of the composition thermally with in the thermally conductive composition, here at least 5% and not more than in, more particularly at least 15% and not m in volume. Since the thermal adjuvant can be porous, the thermally conductive volumetric fraction, it is understood that the volume of the thermal composition is greater than that which occurs when the thermal adjuvant is added to the thermal composition, based on the final volume of the thermal adjuvant. Thermally conductive composition after volumetric adduction is therefore based on the thermally conductive adjuvant in the same form as it is present in the thermal composition). The volumetric fraction can be convections of the corresponding mass of the form Examples and / or elements that have a greater degree olume in the crystalline form, the examples atoms, oxides, carbides, nitrides, silicilides, ex before.

As a thermally conductive adjuvant is example, use aluminum oxide (Al203), ni (BN), silicon dioxide (Si02), titanium boride), silicon nitride (Si3N4), magnesium titanium dioxide (MgO), oxide of nickel (II) (NiO), (II) (CuO), and iron (III) oxide (Fe203), non-metallic metals, examples are Z Y2 3), aluminum titanate (Al2Ti05), nitride), boron carbide (B4C), cordierite, silicon carbide, bonded by the reaction of unsintered silicon under pressure (SSiC), hot compressed silicon (HPSiC), carbide Individual volumetric devices delimited between external dimensions that are very small, for example, powders, materials, and fine pulverized materials, with suns, aerosols, and the like. The a particle does not depend fundamentally on the p has a particular internal structure particular alinity, a factor of the particular external part orma form - regular or irregular-.

Among the thermally conditioned adjuvants, those which have arisen as particularly useful are those consisting of part of the aluminum oxide particles and boron nitride particles, in other shovels of any desired aluminum oxide or boron oxide. wanted.

Also the so called mainly "oxide nio" (Na20 * 11 Al203).

In order to confine the dimensions of these particles, it can be useful if only particles are used that have a diameter ranging from 2 μt? up to 500 icularly from a range of 2 μp? up to 2 from a range from 40 μp? up to 150 μ ?? The dio means an average particle diameter of a particle size distribution, gave mass or a numerical average, and this diameter can also be identical with the single particle in the case where only or particle exists (ie , a monodi ugar substance of this, the average particle diameter be defined as a D50 value, in other pal Those which are customary for the purpose, by means of the analysis of the micro example images, the images obtained from the mic, including ultramicroscopy, of the micronic or scanning microscopy, diffraction or dispersion of the romagnetic (for example, diffraction or laser beam, or diffraction / dispersion of the scattering at small angles), ions of sedimentation, such as by ltracentrifuge, and the like.

For the present invention to obtain that the particles have a surface area based on the mass of 1.3 m2 / g or still less than 1.0 m2 / g. The supreme area of the particles is the whole In other words, the surface area pre-quantity of the sample of a mass of 1 g. Tipi areas of the specific surfaces are deteio of the sorption method (determination of BET absorption and desorption of a gas of purely nitrogen, helium or mercury) s available from the sample are subsequently investigated, when the nitride is used. Acceptable thermal activity has been observed at a specific surface area of up to 5 m2 / g, and a regional one in the specific surface area up to 1.3 m2 / g leads to an increase in thermal conductivity.

In addition, it is necessary for the purpose that the thermally conductive particles are themselves primary particles. One p ctas The composite particles of the lines are present in the desired three-dimensional shape of a large smaller numbers which are stacked together and joined externally - in the form, by unmatched sacking of the primary particles with each other in the edges and angles, and with total surface virtually identical to the sum S individual surface, or as a pool of primary particles that are joined together by means of the regions of the surface lateral face smaller than the sum of the rficiales of the primary particles - in the fo lo, therefore, of agglomerates, ag ations, coacervated materials, flo individual primary articles, which in the primary casings of irregular shape, for example, the maximum diameter and the minimum diameter primary cells.

As a result of the construction of the particles from the primary particles, the external surface of the particles is not irregular, but has the plicity of elevations and depressions, the three-dimensional individual structure of these particles in the context of geometry. fractal, to make, for example, using a dimension ual in each case is greater than two and also m Three-dimensional structures with such ple present in the case of a particle that has irregular geometry (not fractal), com However, even under these conditions, because of the small pore diameters of the capillary pressure within these pores, high p, and thus within the particles, also go sections of the surface area of the I leave that they are not covered by the poly composition or both are exposed.

As a result of the structure, the composition thermally not only copes with a high mechanical strength, but at the same time a high conductivity is ensured.

For the materials described above, obtain particles, which can be used with the invention, by various methods, c of the group comprising sensitive adhesives, hot melt adhesives, and two. This can be achieved, for example, by using adhesives that at the same time produce the mechanical force between the two their ion (heat source and heat sink).

The pressure sensitive adhesives. { PS the adhesives that allow the union for a while at room temperature under only a relatively weak ada. In contrast, hot materials (or melt adhesives) is the term used for ions which are introduced into a substrate joint only at elevated temperatures, which is retained even during the cooling at room temperature. The capacity of the union or adhesion. In the adhesion of an adhesive of an identical, it is common to add plasticizers and / or adobes of the bond strength (sticky knowledge) to the adhesive.

Cohesion typically refers to the effect on internal joint retention of one's position taking into account inter molecular and / or intramolecular. Therefore, the cohesion determines the consistency and thickness of the adhesive, which can be determined, such as the viscosity and the residence time. To increase the cohesion of a specific adh manner, it is subjected to additional frequency, for which the constituents (and therefore crosslinkable) Particularly strong inner surface, while applications require a particular adhesion. PSAs and molten materials can additionally be equipped with chemical or physical co-ordination mechanisms.

In the case of liquid adhesives (by wet adhesives carried by the active solvents of the water-based dispersion) a low viscosity solution of the polymer phase to the bonding substrates. In the course of the solvent (the organic solvents or the viscosity of the solution or the dispersion, and thus the substrates of the union are joined by the resulting polymeric film, the aids include, for example, the adhesives, either chemically or physically. of 1 component example zeolites of molecular sieves or alcium), agents for the flow and for the cont, wetting agents such as the active or catalysts, the thermal fillers, and also the fillers for heat treatment.

The adjuvants used may be solid, finely milled, examples of magnesium carbonate, zinc carbonate, barium oxide, titanium dioxide or dioxide examples are talc, mica, silica, silicates inc. Of course, the established substances can also be used.

The pigments used can be na ica or inorganic. All kinds of chemicals or inorganics are contemplated, examples nte comprehensively through the thickness of the blade orma; instead, the element with at least one sublaminar region, electrically insulating.

Examples of the rheological additives are steaming, phyllosilicates (bentonites, for example polyamide of high molecular mass, or os in derivatives of castor oil.

The additives of the adhesion promoters for example, the substances of the midas, epoxides or solanos groups. The improvement in adhesion to be achieved by using such promoters is not due to the adhesion of PSA to a substrate or by, but also to the internal adhesion of the ether to the thermal adjuvant particles. butene and / or isobutene oils, polyvinyl esters, liquid resins and ions based on the raw materials that form the basis for tackifying resins, waxes, silicones and also pol plasticizers such as polyesters or polyurethanes, for example.

The formulation of the thermal composition with the additional constituents, such as before and plasticizers, for example, is the art.

To optimize the thermally conductive technical properties of the invention mixed with resins. Sticky resins worshiped by the strength of the union) for the can be used include, without exception, the sticky existing ones described in the literature. thermally conductive composition resulting requirements. In general, it is possible to use resins that are compatible (soluble) with the corresponding one; Aliphatic hydrocarbon resins, quilaromatic rings, hydrocarbon resins, pure monomers, hydrogenated resin resins, natural functional hydrocarbon resins can all be mentioned.

A further advantageous embodiment of the sheet element can be achieved by adding a filled storage of the heat to at least one of the coolers for storage of the heat in the meantime any filler that has a high thermal property, more particularly than a heat value greater than 0.7 J / gK. As a result As the filler for storage refers to using a "phase change phase" material, with the help of these materials, the short-term peaks in the co are damped, the latent heat stores of this cn being used include the entire of material or phase which are already known to the person examples are low melting point paraffin salts.

The thermally conductive compositions can be used with an effect on producing an element similar to a thermal sheet. The leaf-like elements of this specification are, in particular, customary and suitable structures that have substantially two-dimensional strength. These are highly conductive Where, for example, a thermal composition having properties of the sensing adhesive is used, then the thermally conductive dosing and the bonding of a signal to a heat sink becomes in a particular way.

The thermally conductive composition can be prepared using, without the known and suitable methods. Thus, for example, a polymer can be mixed with the reagents in a typical mixing assembly, or in the molten material, in a device or a twin-screw extruder, for example.

The leaf-shaped elements of the iin can be produced using no exceptions a monomeric or prepolymer precursor of the pol To produce the elements in the form of, for example, for the thermal composition which is first dispersed in the form as for example on a permanent carrier or temporary fabricator (referred to as the coating element in the process). ") / which is a sheet-shaped element again during the operation no longer until the end of the process. In permanent use it is advantageous that a high thermal conductivity, in virtue, which comprises in a similar way thermally conductive. In an elevated manner, the leaf-shaped element also acts as a thermally conductive carrier for rapid heat transport. to be described in greater detail later on to the attached diagrams of the values.

Brief Description of the Figures Figure 1 shows a diagram of the thermal activity of the thermal compositions is shown as a function of the supra-area of the aluminum oxide particles e as a thermally conductive adjuvant, and Figure 2 shows a diagram in which, flush illustrated in Figure 1, the conductivity to thermally conductive composition is graphically a function of average particle size aluminum oxide particles.

Detailed description of the invention The properties of thermal compositions na: EN ISO 18757: 2005) and / or on alumina oxide with ISO 808.

In order to determine the particle size of thermally conductive adjuvants, a static laser dioxide was performed on those ersated in water by means of ultrasound (inst Instruments MasterSizer 2000), the evaluation or according to the Fraunhofer model.

To determine the thermal conductivity of thermally conductive shells with the adducing conductors, a method according to I 7-2 was carried out (specimen thickness: 10 s sides of the heating element similar).

The determination of the resistance to the trica of the elements similar to a leaf of the sponde to ASTM D 3330-04 / ISO 29862: 2007). To ions were carried out at room temperature standardized conditions (to 50% of iva). The detachment test was carried out as a representative example on a single sample of the strength of the joint taking away from an aging time / union time.

Thermally conductive compositions cut from a polymeric composition of thermally conductive adjuvants. The pressure bleach (PSA) used was a PSA of the acrylate polymer comprising 45% by weight of ethylhexyl acrylate, of butyl acrylate, 8% by weight of acrylic acid, or 1% by weight of hydroxyethyl methacrylate. , gone for the expert person. The solvent was removed by means of a degassing extruder from the resultant acrylate polymer.

To produce a thermal composition, the composition of the acrylate polymer was melted and the respective thermal adjuvant was incorporated into the Haake laboratory composition device at a temperature of 100 ° C. The thermal conductive volume was selected in e so that 40% of the volume of the mixed conductive conductor could be counted before thermally conductive.

To produce the elements similar to a pressure-sensitive ivo, thermally conductive thermal conductivity obtained earlier In contrast to the thermally conductive aluminum oxide particles, these compositions only relate to the specific structure of the aluminum particles. It is noted that results have been obtained if other systems are also used with other polymers. 1 Examples of the invention Comparative examples: In this table, in addition to the number of sample samples (samples 1-3 as an example and samples 4-11 as examples comparativdad based on the volume of the alumina oxide yuvante (content of), the surface area is a in the mass of the adjuvant (BET), the average size and the average particle size (the latter as the D50 value), and the thermal properties of the resulting thermal compositions are listed.

Figure 1 shows the results of the correlation of the thermal conductivity and the suppository area (BET) weighted in the mass of the adjuvant. Figure 1 serves in this case only as a visual tation. ayor.

Figure 2 shows the results of the thermal conductivity thermal conductivity correlation and the average diameter (D50) of the auxiliary. Of the fact that the samples with the surface area are small (samples 1, 2 and 3) have significantly higher conductivity, due ficial, than the samples with a larger supra-area (samples 4 and 5, for example) , thermal conductivity is not córrelmatically with the average particle diameter It is true that the specific surface area of up to a certain degree of particle size larger tends to lead to specific surface based on the smaller mass other samples.

In addition, it is evident from Table 1 that, based on acrylate, as a commonly conductive polymerit was possible to obtain a system in which only the alpha-aluminum oxide was used in practice, the thermally conductive compositions 1-8 were very high, in which the amount of oxide in the adjuvant was greater than 95%, It easily leads to the composition in the coating, and, subsequently, to the compression adhesive film. For samples 9, 10, aste, in which there is also present and / or beta-aluminum, a severe thermally conductive crosslinking has occurred while in the apparatus of the composition, and The determination of the strength of the binding substrates was carried out on a non-crosslinked thermal bonding duration of the bonding period of 14 days, especially ra 2. On a substrate of polar steel, the bond to bond determined in this manner was of 18. a polyamide substrate was 8.5 N / cm, and apolar polyethylene time was still 0.75 N of the resistance measurement d stran that the thermally bonded composition as an example exhibits a pressure sensitive function. Good enough is adequate to produce a similar, thermally conductive element of the sensing adhesive.

The test of the breaking strength e Outstanding ability of the thermal compositions of the invention and also of the thermally conductive foils, as systems for trans alor.

It is noted that in relation to this method known to the applicant for carrying out the aforementioned invention, it is the result of a description of the invention.

Claims

CLAIMS The invention having been described as anti as property contained in the ndications: 1. A thermally conductive composition comprises at least one polymer and a thermal adjuvant, characterized in that: The thermally conductive adjuvant contains particles that are composed of primary particles in a specific surface area based on 2 μg or less. 2. The thermally conductive composition with claim 1, characterized primary cells have an average diameter of more particularly at least 2 μt ?. 3. The composition thermally conducts 5. The thermally conductive composition according to claim 4, characterized by aluminum oxide particles are composed of more than 95% by weight of alpha-a oxide in a fraction of 97% by weight or 6. The thermally conductive composition with any of the claims Cited because the material of the thermal adjuvant has a thermal conductivity of more than particularly greater than 10 W / mK or even more. 7. The thermally conductive composition with any of the claims Cetized because the thermally conductive adjuvant was in the thermally conductive composition in a range from 2 μt? even in a range from 40 μt? up to 150 μp? 9. The thermally conductive composition with any of the claims characterized in that the composition is thermally in the form of an adhesive, more particularly a member of the group comprising the adhesive adhesives, the hot melt adhesives and liquid adhesives. 10. The thermally conductive composition with any of the claims terized because at least one polymer is one or in the acrylic esters, methacrylic esters thereof. 11. The thermally conductive composition with any of the claims ndications 1 to 11.

1 . The use of a thermal composition in accordance with any of the provisions 1 to 11 for the transport of heat or electronic devices.